Steel 4047-HR (Hot rolled)
Supply condition
AISI/SAE 4047 · UNS G40470
Cheapest mill condition for stock that will be normalized or quenched and tempered later.
Values for the HR condition
Other 4047 tempers and conditions
4047 is listed in 11 conditions; see the grade overview at 4047.
Compare all 11 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Spheroidize annealed | Pick for cold-headed fastener blanks where maximum ductility at this carbon level is needed. | 360 | 570 | 26 | 170 HB | 8 % IACS |
ADefault Solution annealed | Choose for rough machining, cold sawing and stock that will be heat treated after fabrication. | 400 | 620 | 22 | 185 HB | — |
HRThis page Hot rolled | Cheapest mill condition for stock that will be normalized or quenched and tempered later. | 430 | 730 | 19 | 17 HRC | 7.8 % IACS |
Normalized | Use to refine grain and homogenize forgings before hardening, or as a moderate-strength as-supplied condition. | 510 | 810 | 19 | 21 HRC | 7.8 % IACS |
Cold drawn | Choose for close-tolerance bright bar with higher yield strength and better surface finish than hot rolled. | 650 | 760 | 12 | 19 HRC | 7.8 % IACS |
Q&T 650 °C | Softest Q&T condition — pick when toughness, machinability or sour-service hardness caps (<22–25 HRC) matter more than strength. | 740 | 860 | 22 | 24 HRC | — |
Induction hardened & tempered surface | Use when a wear-resistant 55+ HRC case with a tough core is needed on shafts, pins or gear journals. | 900 | 1,050 | 14 | 56 HRC | 7.2 % IACS |
Q&T 540 °C | General-purpose quenched-and-tempered condition: good strength with usable toughness and machinability. | 950 | 1,050 | 18 | 33 HRC | — |
Q&T 425 °C | Balanced high-strength condition for shafts, studs and Grade 8-class fasteners. | 1,170 | 1,290 | 14 | 41 HRC | — |
Q&T 315 °C | High-hardness spring/tool-like condition; keep out of the 260–370 °C blue-brittleness zone for impact-loaded parts. | 1,330 | 1,580 | 11 | 47 HRC | — |
Q&T 205 °C | Maximum hardness/wear condition for small sections; very low toughness, avoid where impact or notches exist. | 1,450 | 1,830 | 9 | 51 HRC | — |
What is 4047-HR?
4047-HR is 4047 supplied in the HR condition — cheapest mill condition for stock that will be normalized or quenched and tempered later. 4047-HR has a yield strength of 430 MPa (62.4 ksi) and a tensile strength of 730 MPa (106 ksi) — weaker than 51% of steel grades. Elongation at break is 19% and the elastic modulus is 205 GPa (29.7 Msi). 4047-HR has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F). A is the default condition FabDigit quotes; HR is available on request or by drawing note.
Limitations
- Low fracture toughness — 50 MPa·√m (45.5 ksi·√in), worse than 86% of steel grades
4047-HR properties
Typical room-temperature values for 4047-HR; 23 are specific to this condition. Other listed values are 4047 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
4047-HR has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical16
4047-HR has a yield strength of 430 MPa (62.4 ksi) and a tensile strength of 730 MPa (106 ksi) — weaker than 51% of steel grades. Elongation at break is 19% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
4047-HR is rated for continuous service to 400°C (752 °F). It conducts heat at 43 W/m·K (24.8 BTU/hr·ft·°F), better than 51% of steel grades. Thermal expansion is 12.2 µm/m·K (6.78 µin/in·°F).
Electrical3
4047-HR conducts electricity at 7.8 % IACS, worse than 57% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (11/100), worse than 73% of steel grades.
Sustainability4
Producing a kilogram of 4047-HR takes about 29 MJ of energy and emits 2 kg of CO₂ — less than 53% of steel grades. Typical recycled content is 30%.
Manufacturability6
4047-HR's machinability is fair (52/100, better than 52% of steel grades); weldability poor (28/100); formability poor (28/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 4047-HR
Is 4047 easy to machine?
Machine in the annealed or ≤32 HRC condition with carbide tooling and rigid setups; above 40 HRC switch to CBN/ceramic or grind, and expect roughly half the tool life of 1045.
Can 4047 be welded?
Difficult — CE ≈ 0.65–0.70; preheat 300–400 °C, use low-hydrogen consumables, keep interpass temperature and temper immediately after welding to avoid hydrogen and quench cracking.
Can 4047 be formed, bent or molded?
Cold form only in the spheroidize-annealed condition (upsetting of fastener blanks); otherwise hot forge at 1050–1200 °C and normalize afterwards.
What surface finishes work on 4047?
No corrosion resistance of its own: use black oxide, phosphate + oil, zinc/zinc-nickel plating (bake at 190–200 °C within 4 h if above ~1000 MPa) or paint; hardened surfaces polish and hard-chrome plate well.
4047 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Chighest carbon of the 40xx series | 0.45 – 0.5 | 0.47 |
| Mn | 0.7 – 0.9 | 0.8 |
| Sifor fine-grain killed steel | 0.15 – 0.35 | 0.25 |
| Mohardenability + temper-embrittlement resistance | 0.2 – 0.3 | 0.25 |
| P | ≤ 0.04 | — |
| Smax (H-grades / resulfurized variants differ) | ≤ 0.04 | — |
| Fe | balance | — |
4047-HR — frequently asked
What is 4047-HR used for?
4047-HR is typically used for high-strength bolts, springs and fasteners. In short: highest-carbon 40xx grade; fastener-oriented alloy steel; difficult to weld.
What is the yield strength of 4047-HR?
4047-HR has a typical yield strength of 430 MPa (62.4 ksi) and a tensile strength of 730 MPa (106 ksi) — weaker than 51% of steel grades. Strength varies by condition: see the 11 listed tempers.
Is 4047-HR easy to machine?
Reasonably — machinability is rated fair (52/100, better than 52% of steel grades). Machine in the annealed or ≤32 HRC condition with carbide tooling and rigid setups; above 40 HRC switch to CBN/ceramic or grind, and expect roughly half the tool life of 1045.
Can 4047-HR be welded?
Not readily — weldability is rated poor (28/100). Difficult — CE ≈ 0.65–0.70; preheat 300–400 °C, use low-hydrogen consumables, keep interpass temperature and temper immediately after welding to avoid hydrogen and quench cracking.
What surface finishes work on 4047-HR?
No corrosion resistance of its own: use black oxide, phosphate + oil, zinc/zinc-nickel plating (bake at 190–200 °C within 4 h if above ~1000 MPa) or paint; hardened surfaces polish and hard-chrome plate well.
Can 4047-HR be formed, bent or molded?
Cold form only in the spheroidize-annealed condition (upsetting of fastener blanks); otherwise hot forge at 1050–1200 °C and normalize afterwards.
What is the maximum service temperature of 4047-HR?
4047-HR is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 4047-A and 4047-QT205?
A is the default condition — choose for rough machining, cold sawing and stock that will be heat treated after fabrication. QT205: maximum hardness/wear condition for small sections; very low toughness, avoid where impact or notches exist. Yield strength is 400 MPa in A versus 1,450 MPa in QT205.
Sources
- SAE J404 — Chemical Compositions of SAE Alloy Steels — SAE International (2021)
- ASTM A29/A29M — General Requirements for Steel Bars, Carbon and Alloy, Hot-Wrought — ASTM International (2020)
- SAE J1268 — Hardenability Bands for Carbon and Alloy H Steels — SAE International (2019)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.4 — Heat Treating — ASM International (1991)
- Machinery's Handbook, 31st ed. — Industrial Press (2020)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.